The present invention relates to antenna arrays, and more particularly to conformal arrays useful for missile applications.
U.S. Pat. No. 5,023,623, entitled "Dual Mode Antenna Apparatus Having Slotted Waveguide and Broadband Arrays," by Donald E. Kreinheder et al., the entire contents of which are incorporated herein by this reference, provides a description of conventional missile target detection and tracking systems. Briefly, one type of target tracking system is known as broadband anti-radiation homing (ARH). Such a system is passive, and tracks a target by receiving radiation emitted by the target.
Known conformal arrays for missiles employ conformal slot radiators and microstrip patch radiators. These antennas are narrow band, and because of their physical and/or electrical characteristics they can not be inclined to enhance their forward radiation. The result is a limited field of view.
Conventional conformal mounting situates the antenna elements so they face normal to the missile surface resulting in poor radiation in the forward direction. This is because the antenna is situated so that the greatest amount of energy from each element is directed normally to the missile body. This makes radiation in the forward direction difficult. The problem is made worse for elements radiating with an E-field tangential to the metallic missile body. The metal surface will not support these fields and forces them to zero at the point of contact. This is a major problem for conformal arrays since their "view" to missile boresight is tangential from the cylindrical section and nearly tangential in the nose region.
It is an object of the present invention to provide an ARH missile guidance antenna that is conformal to the missile surface, is dual-polarized, and broadband.
Another object is to provide a conformal antenna array for a missile that will sense RF radiation over the forward hemisphere.